The present invention relates to a method and apparatus for winding a yarn into a cross wound package, and having provision for securing the free yarn end to the package at the conclusion of the winding operation.
The spinning of synthetic fibers, especially an automated spinning process, have in the past presented difficulties in protecting the free yarn end of the package removed from the takeup machine at the end of a winding cycle against contamination during its transportation, and in particular, in locating it again after transportation to a further processing station. Until now, attempts known from the prior art and directed to the identification of the yarn end in the winding of an endless filament yarn at the end of a winding cycle, so that it is again easily locatable, have been unsuccessful.
For example, in a method known from DE 40 23 291 A1, the yarn end of a cross-wound package is easier to locate in that for purposes of forming a yarn reserve upon reaching a certain package diameter or a certain amount of yarn, the yarn is guided across the peripheral surface to the tube or along a secant line across the end surface of the package, and subsequently returned to its peripheral surface.
According to the method described in DE 25 06 930 A1, for purposes of facilitating the locating of the yarn end, a yarn reserve is likewise formed at the end of the winding cycle. To this end, the package is removed from the takeup device and rotated slowly in opposite direction to the direction of winding, the yarn end being grasped pneumatically and sucked off by a yarn suction device. Subsequently, the opening of the yarn suction device swings toward one end of the winding tube projecting from the package, whereupon the yarn is delivered by the yarn suction device to the winding tube, or blown into the winding tube, or wound about the end of the Winding tube in that the package is again rotated in its direction of winding.
While the first-mentioned method has not been suitable to ensure a troublefree relocating of the yarn end, it has been possible to use the second method in takeup machines for an automated spinning only after doffing the package from the winding spindle.
In takeup devices, on which the present invention is based, the yarn is lifted out of the yarn traversing mechanism at the end of the winding cycle, and until it is cut, it advances, guided by a suitable auxiliary device, onto the package in a narrow axial region of the decelerating package, thereby forming a bead-shaped, narrow accumulation of yarn (note, for example, DE 23 28 828 C2).
It is therefore the object of this invention to provide a simple and low-cost possibility of securing the free yarn end upon termination of the winding cycle such that it is easy to relocate during the further handling of the package.